The Canadian research firm Sysomos has compiled a billion Tweets of data to identify who is really, really using Twitter. The answer in short form: The people who have experience.

Now, it might be that the people who have experience are also the ones who have come to like it --- and thus use it. But what the data also indicate is a discouragement phase, somewhere between three and six months into using it. The heavy users seem to be in the period up to three months and again after nine.

The data also indicate Twitter is growing more outside the United States than inside it.

Sysomos suggests there now are about 53 million Tweets daily. The total has grown 30 per cent in the last four months alone.